Stapedial prosthesis



July 27, 1965 M. ROBINSON 3,196,462

STAPEDIAL PROSTHES IS Filed Sept. 5, 1961 Mendeii fiaz'nsan,

United States Patent 3,196,462 STAPEDIAL PROSTHESIS Mendell Robinson, 95Forest Ave., Providence, RI. Filed Sept. 5, 1961, Ser. No. 135,843 3Claims. (Cl. 3-1) The present invention relates to a novel and improvedstapedial prosthesis for use in middle ear surgery.

In the healthy and normal ear, the stapes extends from the incus to theoval window, the foot plate of the stapes sitting in the oval window andcovering same. As is well known, the function of the stapes is to carrysound vibrations from the incus to the oval window and inner ear. When apatient becomes affected with otosolerosis, a bony overgrowth of spongyvascular bone, peculiar to the temporal bone, causes the stapes to berigid, whereupon it is unable to vibrate. This condition has long beenone of the contributory causes of deafness.

' In recent years, a technique has been developed wherein the diseasedstapes is removed from the ear and a poly ethylene stapedial prosthesissubstituted in lieu thereof. This technique is known as the Sheastapedectomy-vien graft procedure. Briefly described, this procedureinvolves the use of a cone-shaped hollow polyethylene strut, the largerend of which is positioned on the lenticular process of the incus, whilethe smaller pointed end of the strut bears against a vein graft that ispositioned over the oval window. This technique has resulted in a highpercentage of rehabilitation of patients afflicted with otoscleroticdeafness.

Although the Shea procedure as broadly described above has proven to betremendously beneficial in curing otosclerosis, it has nevertheless beenfound that certain disadvantages exist as a result of the polyethylenestrut which is used in that technique. First of all, there exists thepossibility that polyethylene may be irritating to both animals andhumans, since it has never been definitely proven that this material iscompletely inert. Although clinical tests have never shown polyethyleneas having an undesirable reaction with the human body, the fact stillremains that tests have shown that this material can be irritating whenimplanted in certain animals, and hence the possibility does exist thatover extended periods of time it may turn out that polyethylene doeshave a reaction when implanted in the human body. In addition, shouldthe polyethylene strut become detached from the incus, there would be noway of determining this dislocation without surgical reexpl-oration ofthe middle ear since polyethylene is not radiopaque. Also, polyethylenecannot be autoclaved but rather can only be sterilized by a rathercomplicated and expensive atomic process. Lastly, polyethylene does nothave maximum vibratory characteristics.

It is therefore a primary object of this invention to provide a noveland improved stapedial prosthesis which may be. used in place of thepolyethylene strut used in the above described Shea stapedectomy-veingraft procedure.

It is a further object of my invention to provide a novel and improvedstapedial prosthesis which is constructed of a material that has minimaltissue reaction to the human body.

Another object of my invention is the provision of a novel and improvedstapedial prosthesis that has greater vibratory quality than thepolyethylene strut heretofore used.

A further object is the provision of a stapedial prosthesis that isconstructed of radiopaque material and hence may be inspected andexamined by X-ray without the necessity of surgical exploration of themiddle ear.

Still another object of my invention is the provision of a novel andimproved stapedial prosthesis that can be autoclaved without difliculty,whereupon absolute sterility of the prosthesis can be maintained.

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A further objects of my invention is the provision of a stapedialprosthesis having means which function to maintain the prosthesisproperly positioned between the incus and the oval window.

Other objects, features and advantages of the invention will becomeapparent as the description thereof proceeds when considered inconnection with the accompanying illustrative drawings.

In the drawings which illustrate the best mode presently contemplated byme for carrying out my invention:

FIG. 1 is a perspective view of a stapedial prosthesis constructed inaccordance with my invention;

FIG. 2 is a section taken on line 22 of FIG. 1, with the wire omitted;

FIG. 3 is a diagrammatic view showing the relationship between theincus, the stapes and the oval window in a normal and healthy ear;

FIG. 4 is a diagrammatic view showing an ear after the stapes has beenremoved;

FIG. 5 is a diagrammatic view showing my stapedial prosthesis inoperative position in the ear; and

FIG. 6 is a diagrammatic view illustrating a slightly modified techniquewith which my stapedial prosthesis may be utilized.

Referring now to the drawings, there is shown generally at 10 astapedial prosthesis constructed in accordance with my invention. Theprosthesis 10 comprises an enlarged proximal portion 12 which is hollow,as shown most clearly in FIG. 2, and which is open at its outer end, asat 14. A reduced shank portion 16 extends axially and centrally fromproximal portion 12, said shank portion being preferably solid. Theprosthesis 10 is preferably of integral, one-piece construction, and itmay be a screw machine part. For reasons which will hereinafter becomeapparent, I prefer to make the prosthesis 10 of stainless steel.

As will be seen most clearly in FIGS. 1 and 2, the proximal portion 12is provided with a pair of openings 18 and 20, said openings extendinglaterally through the proximal portion and being substantiallyperpendicular with respect to each other. A stainless steel wire 22 islooped through one of the aforementioned openings so as to provide apivotal bail which is in spaced relation to the open end 14. At theopposite end of the prosthesis 10, an opening 24 extends laterallythrough the shank portion 16, adjacent the outer end thereof. It isimportant to note that the outer end of shank portion 16 is rounded atits edges, as at 26, so as to eliminate any sharp corners.

Turning now to FIGS. 3 through 6, there is shown in FIG. 3 indiagrammatic form a normal and healthy ear in which the stapes 28extends from the incus 30 to the oval window 32, it being noted that thefoot portion 34 of stapes 28 sits in and blocks said oval window. Thus,the stapes functions as a link for imparting vibrations from the incusto the oval window and inner ear. When, however, the stapes loses itsvibratory characteristics due to the effects of otosclerosis, forexample, the diseased stapes is removed, as illustrated in FIG. 4, andmy prosthesis ltl is substituted in lieu thereof. More specifically,referring to FIG. 5, it will be seen that the hollow open end 14 of theenlarged proximal portion 12 functions as a socket for receiving thelenticular process 36 of the incus so as to form, in effect, a ball andsocket joint therebetween. The wire bail 22 is loosely looped over thelong process 38 of the incus and then may be subsequently tightened tothe desired degree, whereupon the wire func tions as a ligament and actsas an anchor to reinforce the attachment of the prosthesis to the incus.The cross openings 18 and 20 enable mucus membrane to grow into theprosthesis so as to securely anchor it to the incus. In fact, it hasbeen found that the wire 22 is not an absolute necessity in view of theanchor that is eventually obtained by membrane growing into the openings18 and 20.. How-:

ever, the Wire 22 does function to maintain the prosthesis properlypositioned on the incus before the membrane has had a chance to form asecure bond, and'hence'I prefer to utilize the wire bail. t Attheoppositetextremity of the prosthesis 10,.a vein graft, 40 is positionedover the oval window 32 and is-maintained in position thfereover by thepressure exerted by the prosthesis'lo. The rounded-edges 26 at the endof shank portion 10" function to prevent perforation of theoval windowby sharp corners and at parting from the spirit and 'scope of theunderlying inveu-.

tive concept and that the same is not limited to the par- ,ticular formsherein shown and described except insofar as indicated by the scope ofthe appended'claims.

Whatis claimed is: r V -1. A stapedial prosthesis compr-ising anintegral, onepiece body member, said body member havingan enlargedopen-ended tubular proximal portion, and a reduced solid shank portionextending axiallyfrorn' said proximal the same time minimize tissuereaction around the vein graft. The lateral opening 24 facilitates afibrous attach-' ment from the prosthesis to the vein graft.

In FIG. 6, a slightly modified technique islillustrated, wherein insteadof a vein graftbeing used, a fat graft 42 is employed for blocking theoval window. Since the fat 7 graft actually sits within the window, awire 44 is preferably looped through the opening 24 anda-round the 'fatgraft to maintain the latter in proper position; Otherwise,

the construction and use of the prosthesis-shown in FIG. 6 is identicalto that which hasbeenaforedes-cribed.

portion and centrally disposed with-respect thereto, and

a pair of apertures extending laterally through said proximal portion,'the ax-es of said apertures being angularly disposed with respect toeach other;

' 2. A stapedial prosthesis comprising an integral, oneshank portionextending axially from said proximal portion and centrally disposed withrespect thereto, an opening extending laterally throughsaid shankportion ad- As has hereinbefore been set forth, my prosthesis 1 0' is.preferablyconstructed of stainlesssteel since this material has beens-hown'to have minimal tissuenreaction in the jacent the outer endthereof, said outer end being rounded at its edges so asto eliminate anysharpcorners, and a pair'of openings extending laterally through saidproximal portiong'saidlast-mentioned openings-being substantiallyperpendicular with respect to each other; 7 i

J 3. Thestapedial prosthesis of claim 2 furthercharacterized in-that awire loop extendsthrough oneiof said last-mentioned lateral openings soas to provide a pivotal I bail in spaced relation'to the open end ofsaid proximal ered without the necessity of surgery. Stainless steelalso 7 possesses good vibratory characteristics, better thanpolyethylene, for example, and additionally can be autoclaved, which isnot possible with plastic. I-twillbe-understood that my prosthesis 10isrpassivated, electropolished and;

ultrasonically cleaned, whereupon it is' ready for use aftersterilization by autoclaving.

While there is shown and described herein certain spe:

cific structure embodying the invention, it will be'manifest to thoseskilledin the art that various modifications and v rearrangements of'the parts may be made without deportion.- I

I References' Cited by the Examiner V UNITED STATES PATENTS 2, 31,534] 353; Purificato. t 12s 92.2

7 OTH R REFERENCES Prosthetics in Tympanoplasty,by Harrison, Archives ofOtolaryngology, vol; 7 l ,-March 1960,- pages 437442.

ProstheticArticulations in'Stap'es Surgery, by Goodhill,

Archives of Otolaryng ology, vol. 73, March 1961, pages p RICHARD -A.GAUDET, Primmi Examiner.

, piece body member, said body member having an enlarged 'operrendedtubular proximal portion, anda reduced solid

1. A STAPEDIAL PROSTHESIS COMPRISING AN INTEGRAL, ONEPIECE BODY MEMBER,SAID BODY MEMBER HAVING AN ENLARGED OPOEN-ENDED TUBULAR PROXIMALPORTION, AND A REDUCED SOLID SHANK PORTION EXTENDING AXIALLY FROM SAIDPROXIMAL PORTION AND CENTRALLY DISPOSED WITH RESPECT THERETO, AND A PAIROF APERTURES EXTENDING LATERALLY THROUGH SAID PROXIMAL PORTION, THE AXESOF SAID APERTURES BEING ANGULARLY DISPOSED WITH RESPECT TO EACH OTHER.